#ifndef stack_h
#define stack_h 1

#include <optional>
#include <semaphore>
#include <stack>

using namespace std::chrono_literals;

template<class T> class stack
{
public:
    void push(T t)
    {
        semaphore.acquire();
        container.push(t);
        semaphore.release();
    }

    std::optional<T> pop()
    {
        semaphore.acquire();
        if (!container.empty())
        {
            auto data = container.top();
            container.pop();
            semaphore.release();
            return data;
        }
        else
        {
            semaphore.release();
            return std::nullopt;
        }
    }

private:
    std::binary_semaphore semaphore = std::binary_semaphore(1);
    std::stack<T> container;
};

#endif // stack_h